Office of Compensation Analysis and 

Support

Program Evaluation Report 

Document Number: 

 OCAS-PER-002 

Effective Date: 

 12/15/2003 

Revision No. 0 

Error in surrogate organ assignment resulting in an underestimate 

of X-ray dose in SRS dose reconstructions

Page 1 of 4

 

Approval: Signature on File Date: 12/18/2003 J.W. Neton, Associate Director for Science 

Supersedes: 

 None 

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE 

DATE

REV. 

NO.

DESCRIPTION

12/16/2003 12/16/2003 0 

New document to evaluate the programmatic 

effect of an error in surrogate organ assignment 

resulting in a potential underestimate of the X-ray 

dose for certain Savannah River Site (SRS) dose 

reconstructions. 

1.0 Description

On December 4, 2003, an error was discovered in the methodology used in several approved and draft 

Technical Basis Documents (TBDs). For organs not directly listed in ICRP 341

, surrogate organs based 

on anatomical location are assigned for calculation of doses from collimated X-ray examinations. The 

error involves the choice of surrogate organ for the liver, gall bladder, and spleen. The current approved 

TBDs for the Savannah River Site2

 and the Hanford Site3, the approved Complex-Wide X-ray Technical 

Information Bulletin (TIB)4

, and draft TBDs for several sites assigned the ovaries as a surrogate for 

these organs. The more appropriate choice is the lung, based on the proximity of these organs to the 

thoracic cavity (Figure 1). 
Figure 1: Anatomy of human internal organs showing the proximity of the liver, gall

bladder and spleen to the lungs. . -- - -

~

'::...;:-Aorta - Heart

-esopI1agf.1S

- DIaphragm

_Aorta

- ~Ieen

Stomach

".. Pancreas

"-- Small

mstiIW

~L~

iriestine

Rectum

Thyroid ~

Trachea ~

Superlot vena caW--

Lung ~

Liver ---

lnfeoor ~

vena cava .,./

Gallblad~

Kidney

Ureter" -

Appendix

Bladder -

Urethra -

~

'Tt'

2.0 Evaluation

2. 1 Identification of potentially affected claims

On December 10, 2003, the NIOSH OCAS Claims Tracking System (NOCTS) was

queried to determine-which claims could be affected by this error. The considered

claims were limited to those for which:(1) OCAS review had been completed;.(2) the

covered condition was cancer of the liver (ICD-9 code 155, 155.0, 155.2, 197.7,230.8,

235.3), gall bladder (155.1, 156, 156.0,156.1,156.2,156.8,156.9), or spleen (159.1,

197.8); and (3) probability of causation (POC) was less than 50%. This search identified

ten potentially affected claims: four from Bethlehem Steel Corporation, three from the

Savannah River Site, two from Blockson Chemical Company, and one from the

Huntington Pilot Plant. The technical basis documents for Bethlehem Steel5, Blackson

Chemical6 and the Huntington Pilot Plant7 did not contain the error in surrogate organ

dose assignment, therefore only the three claims from the Savannah River Site were

affected.

2.2 Dose Evaluation

The ovaries lie outside the field of typical collimated chest X-rays, while lungs are inside

the field. The result is that dose for the lung is approximately double the dose for the

ovaries 1. Therefore, the error in surrogate organ assignment resulted in an

underestImation of X-ray doses for the liver, gall bladder and spleen. The impact on

assigned organ doses is shown in Table 1 for claims from the Savannah River Site.
Assignment of the correct surrogate organ for the cases from Savannah River Site

resulted in a maximum increase of approximately 43 mrem in the organ dose from each

annual X-ray in the years before 1971. The magnitude of the correction decreased in

later years.

2.2 Probability of Causation Evaluation

The Interactive RadioEpidemiological Program (NIOSH-IREP v.5.2.1) was used to

evaluate the impact on the POC for the three potentially affected cased from the

Savannah River Site. The relevant. characteristics of the three affected cases are shown

in Table 2.

Table 2: The impact on probability of causation of an error in surrogate organ

assianment for the liver and qall bladde~ for claims from the Savannah River Site.

~

a No potentially affected cases Involving cancer of-;e ~ were identified.

b POC = probability of causation. Original PaC is the value with the erroneous surrogate organ assignment

C Revised POC is the value with the corrected surrogate organ assignment

In general, assignment of the lung instead of ovaries as the surrogate organ for the

cases from Savannah River Site resulted in an increase of approximately 0.5% in the

probability of causation value. In none of the three cases did this increase change the

POC value from below 50% to above 50%.

3.0 Resolution/Corrective Action

Since the error in surrogate organ assignment resulted in minimal increases in pac

values (~.5%) for all affected cases, and this increase does not change the probable

compensability status of any claim (i.e. the POC is not increased from <50% to >50%),

no revision of completed dose reconstructions is appropriate at this time.

To preclude recurrence of this error in future dose reconstructions, the ORAU team has

been instructed to revise all affected approved and draft TBDs to ensure that the lung is

assigned as the surrogate organ for the liver, spleen, and gall bladder.

4.0 Summary

An error in surrogate organ assignment for the liver, gall bladder and spleen (ovaries

was assigned instead of lung) resulted in the underestimation of X-ray organ doses in

three completed dose reconstructions. The impact on the probability of causation in

these three cases has been evaluated and found to be minimal (SO.5%), and the

probable compensability status of these claims was unaffected. No revision of any

completed dose reconstructions is warranted, however to preclude Mure occurrences of

this error, revisions of several Technical Basis Documents has been initiated.

5.0 References

1} ICRP, Protection of the Patient in Diagnostic Radiology, ICRP Publication 34,

Pergammon Press, Oxford; England (1983).
ORAU Team, Technical Basis Document forthe Savannah River Site to be Used

for E'E'O/CPA Dose Reconstructions, ORAUT - TKBS-OOO3 Rev 01 (8/21/2003).

2)

3} ORAU Team, Technical Basis Document for the Hanford Site - Occupational

Medical Dose, ORAUT- TKBS-0006-3 Rev 00 (9/16/2003).

4~ ORAU Team, Technicallnfom1ation Bulletin: Dose Reconstruction from

Occupationally Related Diagnostic X-ray Procedures, ORAUT -CTIB-0006, Rev

00 (11/14/2003).

ORAU T earn, Technical Basis Document: Basis for Development of an Exposure

Matrix for Bethlehem Steel Corporation, ORAUT - TKBS-OOO1 Rev O-E

(12/17/2002).

5}

6) ORAU Team, Technical Basis Document: Basis for Development of an Exposure

Matrix for Blockson Chemical Company, ORAUT- TKBS-0002 Rev 00

(10/10/2003).

7) ORAU Team, Technical Basis Document: Basis for Development of an Exposure

Matrix for Huntington Pilot Plant, ORAUT-TKBS-OO04 Rev 00 (10/31/2003).